1. Field of the Invention
This invention relates to a field of aqueous film coating of nutritional supplements and pharmaceutical tablets, and is specifically concerned with providing film coatings based on dextrin for coating nutritional supplements, such as vitamin tablets and herbal tablets, and pharmaceutical tablets, such as acetaminophen (APAP), aspirin (ASA), and Ibuprofen.
2. Description of the Prior Art
Hydroxypropyl methylcellulose, maltodextrin, and lactose have all been used in coatings for substrates such as pharmaceutical tablets. For example, such coatings made from coating compositions manufactured by Colorcon and disclosed in U.S. Pat. Nos. 4,543,370, 4,683,256, 4,643,894, 4,725,441, and 4,828,841, and 5,630,871 all of said patents being incorporated herein by reference, have proven especially effective when used on pharmaceutical tablets.
However, coatings based on hydroxypropyl methylcellulose, maltodextrin, and lactose, especially clear coats (clear non-pigmented coatings), sometimes suffer from a xe2x80x9cfrostingxe2x80x9d problem (the formation of a white frost-like appearance in the coating) when used to coat nutritional supplements like vitamins and herbal tablets. Also, coatings based on hydroxypropyl methylcellulose, maltodextrin, and lactose sometimes suffer from a xe2x80x9cfrostingxe2x80x9d problem when used to coat pharmaceutical tablets (e.g., color-coded APAP tablets) at a 1% weight gain.
Further, coatings based on hydroxypropyl methylcellulose sometime become too brittle and dried out when used to coat herbal tablets, resulting in coatings peeling off the herbal tablets.
Also, coatings based on hydroxypropyl methylcellulose sometimes have a dull matte finish with low gloss, rather than a desirable glossy finish, when used to coat nutritional supplements like vitamins and herbal tablets.
Tapioca dextrin has been used as an ingredient in a sealant layer for chocolates, nuts, etc. in the food/confectionery field, and the sealant layer containing tapioca dextrin is covered with a coating such as a sugar shell. Tapioca dextrin is recognized to be very brittle and very tacky.
It is an object of the invention to provide a film coating that possesses long-lasting gloss, good film adhesion, and good film clarity.
Another object of the invention is to provide a film coating that may be used as a gloss coating for vitamin tablets, herbal tablets, and pharmaceutical tablets that possesses long-lasting gloss, that adheres well to difficult substrates such as calcium-oyster shell, and that is non-frosting and clear.
Another object of the invention is to provide a film coating that eases tablet flow in the bed of a coating pan.
These and other objects are accomplished by our invention, which is described below.